1. Field of Invention
This invention relates to a novel peptide antibiotic and to its use as an antitumor agent. The present invention also relates to a method for the preparation of said antibiotic.
2. Description of the Prior Art
Two U.S. patents, U.S. Pat. No. 4,692,510 (Konishi, et al.), issued Sept. 8, 1987 and U.S. Pat. No. 4,777,160 (Oka, et al.), issued Oct. 11, 1988, disclose peptide antibiotics of formula I
__________________________________________________________________________ ##STR2## I R.sup.1 R.sup.2 Glidobactin __________________________________________________________________________ H CH.sub.3(CH.sub.2).sub.6 A (BU-2867T A) H CH.sub.3(CH.sub.2).sub.4CHCH(CH.sub.2).sub.2 B (BU-2867T B) H CH.sub.3(CH.sub.2).sub.8 C (BU-2867T C) H CH.sub.3(CH.sub.2).sub.4 BU-2867T F OH CH.sub.3(CH.sub.2).sub.6 BU-2867T G __________________________________________________________________________
which are produced by fermentation of Polyangium brachysporum sp. nov., strain K481-B101 (ATCC 53080). The above-mentioned peptide antibiotics were reported as having both antifungal and anti-tumor activities. In general, members of the series are referred to as glidobactins.
Other related art includes U.S. Pat. No. 4,789,731 (Oka, et al.), issued Dec. 6, 1988 and U.S. Pat. No. 4,742,047 (Oka, et al.), issued May 3, 1988, wherein semi-synthetic glidobactins also having anti-tumor properties are disclosed.
Another related art of the instant invention is disclosed in Numata, et al., The Journal of Antibiotics, 41, 10, pp. 1358-1365 (1988) and in U.S. Pat. No. 4,833,076 (Knoishi, et al.), issued May 23, 1989, wherein the authors report enriched production of glidobactins A, B, or C with the addition of certain fat or oil. Furthermore, enhanced production of glidobactins A, B, or C was also observed by precuring palmitoleate, linoleate, or oleate, respectively, to a production medium.